Hostname: page-component-76fb5796d-skm99 Total loading time: 0 Render date: 2024-04-25T11:11:38.468Z Has data issue: false hasContentIssue false
  • English
  • Français

A kinetic model of Phanerozoic taxonomic diversity II. Early Phanerozoic families and multiple equilibria

Published online by Cambridge University Press:  08 February 2016

J. John Sepkoski Jr.
J. John Sepkoski Jr.*
Affiliation:
Department of the Geophysical Sciences, University of Chicago; 5734 South Ellis Ave., Chicago, Illinois 60637
Get access Rights & Permissions [Opens in a new window]

Abstract

The kinetic model of taxonomic diversity predicts that the long-term diversification of taxa within any large and essentially closed ecological system should approximate a logistic process controlled by changes in origination and extinction rates with changing numbers of taxa. This model is tested with a new compilation of numbers of metazoan families known from Paleozoic stages (including stage-level subdivisions of the Cambrian). These data indicate the occurrence of two intervals of logistic diversification within the Paleozoic. The first interval, spanning the Vendian and Cambrian, includes an approximately exponential increase in families across the Precambrian-Cambrian Boundary and a “pseudo-equilibrium” through the Middle and Late Cambrian, caused by diversity-dependent decrease in origination rate and increase in extinction rate. The second interval begins with a rapid re-diversification in the Ordovician, which leads to a tripling of familial diversity during a span of 50 Myr; by the end of the Ordovician diversity attains a new dynamic equilibrium that is maintained, except for several extinction events, for nearly 200 Myr until near the end of the Paleozoic. A “two-phase” kinetic model is constructed to describe this heterogeneous pattern of early Phanerozoic diversification. The model adequately describes the “multiple equilibria,” the asymmetrical history of the “Cambrian fauna,” the extremely slow initial diversification of the later “Paleozoic fauna,” and the combined patterns of origination and extinction in both faunas. It is suggested that this entire pattern of diversification reflects the early success of ecologically generalized taxa and their later replacement by more specialized taxa.

Type
Research Article
Information
Paleobiology , Volume 5 , Issue 3 , Summer 1979 , pp. 222 - 251
Copyright
Copyright © The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Aitken, J. D. 1966. Middle Cambrian to Middle Ordovician cyclic sedimentation, southern Rocky Mountains of Alberta. Can. Petrol. Geol. Bull. 14:405–441.Google Scholar
Alpert, S. P. 1976. Trilobite and star-like trace fossils from the White-Inyo Mountains, California. J. Paleontol. 50:226–239.Google Scholar
Alpert, S. P. 1977. Trace fossils and the basal Cambrian Boundary. Pp. 1–8. In: Crimes, T. P. and Harper, J. C., eds. Trace Fossils 2. 351 pp.Seel House Press; Liverpool.Google Scholar
Anderson, M. M. 1972. A possible time span for the late Precambrian of the Avalon Peninsula, southeastern Newfoundland, in light of worldwide correlation of fossils, tillites, and rock units within the succession. Can. J. Earth Sci. 9:1710–1726.CrossRefGoogle Scholar
Armstrong, R. L. 1978. Pre-Cenozoic Phanerozoic time scale—computer file of critical dates and consequences of new and in-progress decay-constant revisions. Pp. 73–92. In: Cohee, G. V. et al., eds. The Geologic Time Scale. 388 pp.Am. Assoc. Petrol. Geol.; Tulsa, Oklahoma.Google Scholar
Bambach, R. K. 1977. Species richness in marine benthic habitats through the Phanerozoic. Paleobiology. 3:152–167.CrossRefGoogle Scholar
Bayer, T. N. 1967. Repetitive benthonic communities in the Maquoketa Formation (Ordovician) of Minnesota. J. Paleontol. 41:417–422.Google Scholar
Bengtson, S. 1970. The Lower Cambrian fossil Tommotia. Lethaia. 3:363–392.CrossRefGoogle Scholar
Bengtson, S. 1977a. Aspects of problematic fossils in the early Palaeozoic. Acta Universitatis Upsaliensis, No. 415, 71 pp.Google Scholar
Bengtson, S. 1977b. Early Cambrian button-shaped phosphatic microfossils from the Siberian Platform. Palaeontology. 20:751–762.Google Scholar
Berg-Madsen, V. and Peel, J. S. 1978. Middle Cambrian monoplacophorans from Bornholm and Australia, and the systematic position of the bellerophontiform molluscs. Lethaia. 11:113–126.CrossRefGoogle Scholar
Bergström, J. 1973. Organization, life, and systematics of trilobites. Fossils and Strata, No. 2, 69 pp.Google Scholar
Blalock, H. M. Jr. 1964. Causal Inferences in Nonexperimental Research. 200 pp. W. W. Norton & Co.; New York.Google Scholar
Boucot, A. J. 1975a. Standing diversity of fossil groups in successive intervals of geologic time viewed in the light of changing levels of provincialism. J. Paleontol. 49:1105–1111.Google Scholar
Boucot, A. J. 1975b. Evolution and Extinction Rate Controls. 427 pp. Elsevier; Amsterdam.Google Scholar
Bretsky, P. W. 1968. Evolution of Paleozoic marine invertebrate communities. Science. 159:1231–1233.CrossRefGoogle ScholarPubMed
Bretsky, P. W. 1969. Evolution of Paleozoic benthic marine invertebrate communities. Palaeogeogr., Palaeoclimat., Palaeoecol. 6:45–59.CrossRefGoogle Scholar
Bretsky, P. W. 1977. Macroinvertebrate teilzones and episodic faunal changes from an Upper Ordovician flysch in Quebec. Can. J. Earth Sci. 7:1674–1686.CrossRefGoogle Scholar
Brett, C. E. and Liddell, W. D. 1978. Preservation and paleoecology of a Middle Ordovician hardground community. Paleobiology. 4:329–348.CrossRefGoogle Scholar
Briggs, D. E. G. 1977. Evolutionary significance of Canadaspis, the earliest positively identified crustacean. J. Paleontol. 51 (Suppl.):4.Google Scholar
Brown, G. R. 1978. Morphologic complexity and its relationship to taxonomic rates of evolution. J. Undergrad. Res., Univ. Rochester, No. 3, pp. 139–168.Google Scholar
Cisne, J. L. 1974. Evolution of the world fauna of aquatic free-living arthropods. Evolution. 28:337–366.CrossRefGoogle ScholarPubMed
Cloud, P. E. 1968. Pre-metazoan evolution and the origins of the Metazoa. Pp. 1–72. In: Drake, E. T., ed. Evolution and Environment. 470 pp.Yale Univ. Press; New Haven, Connecticut.Google Scholar
Cloud, P. E. 1976. Major features of crustal evolution. Geol. Soc. South Afr. Trans. Annexure to Vol. 79. 32 pp.Google Scholar
Conway Morris, S. 1977a. A new entoproct-like organism from the Burgess Shale of British Columbia. Palaeontology. 20:833–845.Google Scholar
Conway Morris, S. 1977b. A new metazoan from the Cambrian Burgess Shale of British Columbia. Palaeontology. 20:623–640.Google Scholar
Cowie, J. W. 1964. The Cambrian Period. Pp. 255–258. In: Harland, W. B. et al., eds. The Phanerozoic Time-Scale: A Symposium. 458 pp.Geol. Soc. London; London.Google Scholar
Cowie, J. W. and Cribb, S. J. 1978. The Cambrian System. Pp. 355–362. In: Cohee, G. V. et al., eds. The Geologic Time Scale. 388 pp.Am. Assoc. Petrol. Geol.; Tulsa, Oklahoma.Google Scholar
Cowie, J. W. and Glaessner, M. F. 1975. The Precambrian-Cambrian Boundary: A symposium. Earth-Sci. Rev. 11:209–251.CrossRefGoogle Scholar
Cowie, J. W. and Rozanov, A. Yu. 1974. I.U.G.S. Precambrian/Cambrian Boundary working group in Siberia, 1973. Geol. Mag. 111:237–252.CrossRefGoogle Scholar
Cowie, J. W., Rushton, A. W. A., and Stubblefield, C. J. 1972. A correlation of Cambrian rocks in the British Isles. Geol. Soc. London, Spec. Rept. 2, 42 pp.Google Scholar
Cutbill, J. L. and Funnell, B. M. 1967. Computer analysis of The Fossil Record. Pp. 791–820. In: Harland, W. B. et al., eds. The Fossil Record. 828 pp.Geol. Soc. London; London.Google Scholar
Daily, B. 1972. The base of the Cambrian and the first Cambrian faunas. Univ. Adelaide Centre for Precambrian Res., Spec. Pap. No. 1, pp. 13–42.Google Scholar
Daily, B. and Jago, J. B. 1975. The trilobite Lejopyge Hawle and Corda and the Middle-Upper Cambrian Boundary. Palaeontology. 18:527–550.Google Scholar
Debrenne, F. and Debrenne, M. 1978. Archaeocyathid fauna of the lowest fossiliferous levels of Tiout (Lower Cambrian, southern Morocco). Geol. Mag. 115:101–120.CrossRefGoogle Scholar
Fedonkin, M. A. 1977. Precambrian-Cambrian ichnocoenoses of the East European Platform. Pp. 183–194. In: Crimes, T. P. and Harper, J. C., eds. Trace Fossils 2. 351 pp.Seel House Press; Liverpool.Google Scholar
Fox, W. T. 1968. Quantitative paleoecologic analysis of fossil communities in the Richmond Group. J. Geol. 76:613–640.CrossRefGoogle Scholar
Fritz, W. H. 1970. Cambrian faunas. Pp. 593–600. In: Douglas, R. J., ed. Geology and Economic Minerals of Canada. 838 pp.Dept. Energy, Mines, and Res.; Ottawa, Canada.Google Scholar
Fritz, W. H. 1972. Lower Cambrian trilobites from the Sekwi Formation type section, MacKenzie Mountains, northwestern Canada. Can. Geol. Surv. Bull. No. 212, 58 pp.CrossRefGoogle Scholar
Gause, G. F. 1934. The Struggle for Existence. 126 pp. Williams and Wilkins; Baltimore, Maryland.CrossRefGoogle ScholarPubMed
Glaessner, M. F. 1958a. The oldest fossil faunas of South Australia. Geol. Rundsch. 47:522–531.CrossRefGoogle Scholar
Glaessner, M. F. 1958b. New fossils from the base of the Cambrian in South Australia. Trans. R. Soc. S. Aust. 81:185–188.Google Scholar
Glaessner, M. F. 1971a. Geographic distribution and time range of the Ediacara Precambrian fauna. Geol. Soc. Am. Bull. 82:509–514.CrossRefGoogle Scholar
Glaessner, M. F. 1971b. The genus Conomedusites Glaessner & Wade and the diversification of the Cnidaria. Paläontol. Z. 45:7–17.CrossRefGoogle Scholar
Glaessner, M. F. and Wade, M. 1966. The late Precambrian fossils from Ediacara, South Australia. Palaeontology. 9:599–628.Google Scholar
Glaessner, M. F. and Wade, M. 1971. Praecambridium—a primitive arthropod. Lethaia. 4:71–77.CrossRefGoogle Scholar
Gould, S. J. 1977. Eternal metaphors of palaeontology. Pp. 1–26. In: Hallam, A., ed. Patterns of Evolution. 591 pp.Elsevier; Amsterdam.Google Scholar
Gould, S. J., Raup, D. M., Sepkoski, J. J. Jr., Schopf, T. J. M., and Simberloff, D. S. 1977. The shape of evolution: A comparison of real and random clades. Paleobiology. 3:23–40.CrossRefGoogle Scholar
Gritsik, V. V. 1969. Litologo-stratigraficheskii razrez Marchinskoi opornoi skrazhini. Pp. 186–201. In: Zhuravleva, I. T., ed. Biostratigrafiya i Paleontologiya Nizhnego Kembriya Sibiri i Dalbiego Vostoka. 223 pp.Nauka; Moscow.Google Scholar
Harland, W. B., Smith, A. G., and Wilcock, B., eds. 1964. The Phanerozoic Time-scale: A Symposium. 458 pp. Geol. Soc. London; London.Google Scholar
Harland, W. B. et al., eds. 1967. The Fossil Record. 828 pp. Geol. Soc. London; London.Google Scholar
Harper, C. W. Jr. 1975. Standing diversity of fossil groups in successive intervals of geologic time: A new measure. J. Paleontol. 49:752–757.Google Scholar
Harrington, H. J. and Moore, R. C. 1956. Dipleurozoa. Pp. F24–F27. In: Moore, R. C., ed. Treatise on Invertebrate Paleontology, Pt. F. Coelenterata. 498 pp.Geol. Soc. Am. and Univ. Kans. Press; Lawrence, Kansas.Google Scholar
Hill, D. 1972. Archaeocyatha. In: Teichert, C., ed. Treatise on Invertebrate Paleontology, Pt. E, v. 1. 158 pp. Geol. Soc. Am. and Univ. Kans. Press; Lawrence, Kansas.Google Scholar
Hintze, L. F. and Robison, R. A. 1975. Middle Cambrian stratigraphy of the House, Wah Wah, and adjacent ranges in western Utah. Geol. Soc. Am. Bull. 86:881–891.2.0.CO;2>CrossRefGoogle Scholar
Holmes, A. 1959. A revised geological time-scale. Trans. Edinburgh Geol. Soc. 17:183–216.CrossRefGoogle Scholar
Hudson, J. D. 1964. Sedimentation rates in relation to the Phanerozoic time-scale. Pp. 37–42. In: Harland, W. B. et. al., eds. The Phanerozoic Time-scale: A Symposium. 458 pp.Geol. Soc. London; London.Google Scholar
Hupé, P. 1960. Sur le cambrien inférieur du Maroc. 21st Int. Geol. Congr., Copenhagen. Rep., Pt. 8, pp. 75–85.Google Scholar
Jell, P. A. and Jell, J. S. 1976. Early Middle Cambrian corals from western New South Wales. Alcheringa. 1:181–195.CrossRefGoogle Scholar
Kobayashi, T. 1966. The Cambro-Ordovician formations and faunas of South Korea. Part X. Stratigraphy of the Chosen Group in Korea and South Manchuria. Section B. The Chosen Group of North Korea and northeast China. J. Fac. Sci., Univ. Tokyo, Sec. 11. 16:209–311.Google Scholar
Kobayashi, T. 1971. The Cambro-Ordovician faunal provinces and the interprovincial correlation. J. Fac. Sci., Univ. Tokyo, Sec. 11. 18:129–299.Google Scholar
Lambert, R. St. J. 1971. The pre-Pleistocene Phanerozoic time scale—a review. Pp. 9–31. In: Harland, W. B. and Francis, E. H., eds. The Phanerozoic Time-scale, A Supplement. 356 pp.Geol. Soc. London; London.Google Scholar
Landing, E., Taylor, M. E., and Erdtmann, B.-D. 1978. Correlation of the Cambrian-Ordovician Boundary between the Acado-Baltic and North American provinces. Geology. 6:75–78.2.0.CO;2>CrossRefGoogle Scholar
Lasker, H. 1978. The measurement of taxonomic evolution: Preservational biases. Paleobiology. 4:135–149.CrossRefGoogle Scholar
Levinton, J. S. 1974. Trophic group and evolution in bivalve molluscs. Palaeontology. 17:579–586.Google Scholar
Levinton, J. S. 1979. A theory of diversity equilibrium and morphological evolution. Science. 204:335–336.CrossRefGoogle ScholarPubMed
Levinton, J. S. and Bambach, R. K. 1975. A comparative study of Silurian and Recent deposit-feeding bivalve communities. Paleobiology. 1:97–124.CrossRefGoogle Scholar
Lochman-Balk, C. 1971. The Cambrian of the craton of the United States. Pp. 79–167. In: Holland, C. H., ed. Cambrian of the New World. 456 pp.Wiley-Interscience; New York.Google Scholar
Lochman-Balk, C., and Wilson, J. L. 1958. Cambrian biostratigraphy in North America. J. Paleontol. 32:312–350.Google Scholar
MacArthur, R. H. 1969. Patterns of communities in the tropics. Biol. J. Linn. Soc. 1:19–30.CrossRefGoogle Scholar
MacArthur, R. H. and Wilson, E. O. 1963. An equilibrium theory of insular zoogeography. Evolution. 17:373–387.CrossRefGoogle Scholar
MacArthur, R. H. and Wilson, E. O. 1967. The Theory of Island Biogeography. Monogr. Population Biol., No. 1. 203 pp. Princeton Univ. Press; Princeton, New Jersey.Google Scholar
Martinsson, A. 1974. The Cambrian of Norden. Pp. 185–283. In: Holland, C. H., ed. Cambrian of the British Isles, Norden and Spitsbergen. 300 pp.Wiley-Interscience; New York.Google Scholar
Matthews, S. C. and Missarzhevsky, V. V. 1975. Small shelly fossils of late Precambrian and Early Cambrian age: A review of recent work. J. Geol. Soc. London. 131:289–304.CrossRefGoogle Scholar
McBride, D. J. 1976. Outer shelf communities and trophic groups in the Upper Cambrian of the Great Basin. Pp. 139–152. In: Robison, R. A. and Rowell, A. J., eds. Paleontology and Depositional Environments: Cambrian of Western North America. 227 pp.Brigham Young Univ. Geol. Studies. 23(2).Google Scholar
McKerrow, W. S., ed. 1978. The Ecology of Fossils. 384 pp. The MIT Press; Cambridge, Massachusetts.Google Scholar
Moore, R. C. and Teichert, C., eds. 1953-1979. Treatise on Invertebrate Paleontology. Geol. Soc. Am. and Univ. Kans. Press; Lawrence, Kansas.Google Scholar
Nalivkin, D. V. 1973. Geology of the U.S.S.R. (Rast, N., trans.). 855 pp. Univ. Toronto Press; Toronto.Google Scholar
Newell, N. D. 1952. Periodicity in invertebrate evolution. J. Paleontol. 26:371–385.Google Scholar
Newell, N. D. 1967. Revolutions in the history of life. Geol. Soc. Am. Spec. Pap. 89:63–91.Google Scholar
Nitecki, M. H. 1970. North American cyclocrinitid algae. Fieldiana: Geol. 21, 82 pp.Google Scholar
Nitecki, M. H. 1972. North American Silurian receptaculitid algae. Fieldiana: Geol. 28, 108 pp.Google Scholar
Nitecki, M. H. and Debrenne, F. 1979. The nature of radiocyathids and their relationship to receptaculitids and archaeocyathids. Geobios. 12:5–27.CrossRefGoogle Scholar
North, F. K. 1971. The Cambrian of Canada and Alaska. Pp. 219–324. In: Holland, C. H., ed. Cambrian of the New World. 456 pp.Wiley-Interscience; New York.Google Scholar
Öpik, A. A. 1966. The early Upper Cambrian crisis and its correlation. J. Proc. R. Soc. New S. Wales. 100:9–14.CrossRefGoogle Scholar
Öpik, A. A. 1967a. The Ordian Stage of the Cambrian and its Australian Metadoxididae. Aust. Bur. Miner. Res., Geol. and Geophys., Bull. 92:133–169.Google Scholar
Öpik, A. A. 1967b. The Mindyallan fauna of north-western Queensland. Aust. Bur. Miner. Res., Geol. and Geophys., Bull. 74:571 pp.Google Scholar
Öpik, A. A. 1968. Ordian (Cambrian) Crustacea Bradoriida of Australia. Aust. Bur. Miner. Res., Geol. and Geophys., Bull. 103:1–44.Google Scholar
Öpik, A. A. 1975. Cymbric Vale fauna of New South Wales and Early Cambrian biostratigraphy. Aust. Bur. Miner. Res., Geol. and Geophys., Bull. 159:1–74.Google Scholar
Palmer, A. R. 1956. The Cambrian System of the Great Basin in western United States. Pp. 663–681. In: Rodgers, J., ed. El Sistema Cámbrico. Pt. 2. 20th Int. Geol. Congr.; México.Google Scholar
Palmer, A. R. 1965. Biomere, a new kind of biostratigraphic unit. J. Paleontol. 39:149–153.Google Scholar
Palmer, A. R. 1969. Cambrian trilobite distributions in North America and their bearing on Cambrian paleogeography of Newfoundland. Pp. 139–144. In: Kay, M., ed. North Atlantic—Geology and Continental Drift. 1082 pp.Am. Assoc. Petrol. Geol. Mem. 12; Tulsa, Oklahoma.Google Scholar
Palmer, A.R. 1971. The Cambrian of the Great Basin and adjacent areas, western United States. Pp. 1–78. In: Holland, C. H., ed. Cambrian of the New World. 456 pp.Wiley-Interscience; New York.Google Scholar
Palmer, A. R. 1977. Biostratigraphy of the Cambrian System—a progress report. Annu. Rev. Earth and Planet. Sci. 5:13–33.CrossRefGoogle Scholar
Palmer, T. J. and Palmer, C. D. 1977. Faunal distribution and colonization strategy in a Middle Ordovician hardground community. Lethaia. 10:179–200.CrossRefGoogle Scholar
Paul, C. R. C. 1977. Evolution of primitive echinoderms. Pp. 124–158. In: Hallam, A., ed. Patterns of Evolution. 591 pp.Elsevier; Amsterdam.Google Scholar
Pflug, H. D. 1972. The Phanerozoic-Cryptozoic Boundary and the origin of Metazoa. 24th Int. Geol. Congr., Montreal, Sec. 1, pp. 58–67.Google Scholar
Pitcher, M. 1964. Evolution of Chazyan (Ordovician) reefs of eastern U.S. and Canada. Can. Petrol. Geol. Bull. 12:632–691.Google Scholar
Pitcher, M. 1971. Middle Ordovician reef assemblages. N. Am. Paleontol. Conv., Chicago, 1969. Proc., Pt. J, pp. 1341–1357.Google Scholar
Pojeta, J. 1971. Review of Ordovician pelecypods. U.S. Geol. Surv. Prof. Pap. 695, 46 pp.CrossRefGoogle Scholar
Pojeta, J. 1975. Fordilla troyensis Barrande and early pelecypod phylogeny. Bull. Amer. Paleontol. 67:363–384.Google Scholar
Pojeta, J. and Runnegar, B. 1976. The paleontology of rostroconch mollusks and the early history of the phylum Mollusca. U.S. Geol. Surv. Prof. Pap. 968, 88 pp.Google Scholar
Preston, F. W. 1962. The canonical distribution of commonness and rarity. Ecology. 43:185–215and 410-432.CrossRefGoogle Scholar
Raup, D. M. 1972. Taxonomic diversity during the Phanerozoic. Science. 177:1065–1071.CrossRefGoogle ScholarPubMed
Raup, D. M. 1976. Species diversity in the Phanerozoic: A tabulation. Paleobiology. 2:279–288.CrossRefGoogle Scholar
Raup, D. M. 1978. Cohort analysis of generic survivorship. Paleobiology. 4:1–15.CrossRefGoogle Scholar
Raup, D. M., Gould, S. J., Schopf, T. J. M., and Simberloff, D. S. 1973. Stochastic models of phylogeny and the evolution of diversity. J. Geol. 81:525–542.CrossRefGoogle Scholar
Raup, D. M. and Stanley, S. M. 1978. Principles of Paleontology, 2nd ed.481 pp. W. H. Freeman and Co.; San Francisco.Google Scholar
Repina, L. N. 1974. K voprosy o granitse Nizhnego i Srednego Kembriya Sibirskoy Platformy i sopredel'nykh territory. Pp. 76–103. In: Zhuravleva, I. T. and Rozanov, A. Yu., eds. Biostratigrafiya i Paleontologiya Nizhnego Kembriya Evropy i Severnoy Asii. 311 pp.Nauka; Moscow.Google Scholar
Richards, R. P. 1972. Autecology of Richmondian brachiopods (Late Ordovician) of Indiana and Ohio. J. Paleontol. 46:386–405.Google Scholar
Richter, R. 1955. Die ältesten Fossilien Süd-Afrikas. Senckenberg. Leth. 36:243–289.Google Scholar
Robison, R. A. 1960. Lower and Middle Cambrian stratigraphy of the eastern Great Basin. Intermountain Assoc. Petrol. Geol., E. Nev. Geol. Soc. Joint Field Conf., Guidebook. Pp. 43–52.Google Scholar
Robison, R. A. 1975. Species diversity among agnostid trilobites. Pp. 219–226. In: Martinsson, A., ed. Evolution and Morphology of the Trilobita, Trilobitoidea and Merstomata. 467 pp.Fossils and Strata No. 4.Google Scholar
Robison, R. A., Rosova, A. V., Rowell, A. J., and Fletcher, T. P. 1977. Cambrian boundaries and divisions. Lethaia. 10:257–262.CrossRefGoogle Scholar
Rosenzweig, M. L. 1975. On continental steady states of species diversity. Pp. 121–140. In: Cody, M. L. and Diamond, J. M., eds. Ecology and Evolution of Communities. 544 pp.Belknap Press; Cambridge, Massachusetts.Google Scholar
Rowell, A. J. 1977. Early Cambrian brachiopods from the southwestern Great Basin of California and Nevada. J. Paleontol. 51:68–85.Google Scholar
Rozanov, A. Yu. and Debrenne, F. 1974. Age of archaeocyathid assemblages. Am. J. Sci. 274:833–848.CrossRefGoogle Scholar
Rozanov, A. Yu., Missarzhevsky, V. V., Volkova, N. A., Voronova, L. G., Krylov, I. N., Keller, B. M., Korolyuk, I. K., Lendzion, K., Mikhiak, P., Pykhova, N. G., and Sidorov, A. D. 1969. Tommotsky yarus i problema nizhney granitsy Kembria. Trans. Geol. Inst. Acad. Sci. USSR. 206:5–380.Google Scholar
Runnegar, B. and Jell, P. A. 1976. Australian Middle Cambrian molluscs and their bearing on early molluscan evolution. Alcheringa. 1:109–138.CrossRefGoogle Scholar
Runnegar, B. and Pojeta, J. 1974. Molluscan phylogeny: The paleontological viewpoint. Science. 186:311–317.CrossRefGoogle ScholarPubMed
Rushton, A. W. A. 1974. The Cambrian of Wales and England. Pp. 43–121. In: Holland, C. H., ed. Cambrian of the British Isles, Norden and Spitsbergen. 300 pp.Wiley-Interscience; New York.Google Scholar
Salop, L. J. 1977. Precambrian of the Northern Hemisphere. 378 pp. Elsevier; Amsterdam.Google Scholar
Schmitt, M. 1978. Stromatolites from the Tiout section, Precambrian-Cambrian Boundary beds, Anti-Atlas, Morocco. Geol. Mag. 115:95–100.CrossRefGoogle Scholar
Sdzuy, K. 1978. The Precambrian-Cambrian Boundary beds in Morocco (preliminary report). Geol. Mag. 115:83–94.CrossRefGoogle Scholar
Sepkoski, J. J. Jr. 1978. A kinetic model of Phanerozoic taxonomic diversity. I. Analysis of marine orders. Paleobiology. 4:223–251.CrossRefGoogle Scholar
Simpson, G. G. 1944. Tempo and Mode in Evolution. 237 pp. Columbia Univ. Press; New York.Google Scholar
Simpson, G. G. 1953. The Major Features of Evolution. 434 pp. Columbia Univ. Press; New York.CrossRefGoogle Scholar
Sokolov, B. S. 1972. The Wendian Stage in Earth history. 24th Int. Geol. Congr., Montreal, Sec. 1, pp. 78–84.Google Scholar
Sokolov, B. S. 1973. Vendian of northern Eurasia. Pp. 204–218. In: Pitcher, M. G., ed. Arctic Geology. 740 pp.Am. Assoc. Petrol. Geol.; Tulsa, Oklahoma.Google Scholar
Sokolov, B. S. 1976. Precambrian Metazoa and the Vendian-Cambrian Boundary. Paleontol. J. 10:1–13.Google Scholar
Sprigg, R. C. 1947. Early Cambrian (?) jellyfishes from the Flinders Ranges, South Australia. Trans. R. Soc. S. Aust. 71:219–224.Google Scholar
Sprinkle, J. 1973. Morphology and evolution of blastozoan echinoderms. Spec. Publ. Mus. Comp. Zool., Harvard Univ. 283 pp.Google Scholar
Sprinkle, J. 1976. Biostratigraphy and paleoecology of Cambrian echinoderms from the Rocky Mountains. Pp. 61–73. In: Robison, R. A. and Rowell, A. J., eds. Paleontology and Depositional Environments: Cambrian of Western North America. 227 pp.Brigham Young Geol. Studies. 22(2).Google Scholar
Stanley, S. M. 1973. Effects of competition on rates of evolution, with special reference to bivalve mollusks and mammals. Syst. Zool. 22:486–506.CrossRefGoogle Scholar
Stanley, S. M. 1976. Fossil data and the Precambrian-Cambrian evolutionary transition. Am. J. Sci. 276:56–76.CrossRefGoogle Scholar
Stanley, S. M. 1977. Trends, rates, and patterns of evolution in the Bivalvia. Pp. 209–250. In: Hallam, A., ed. Patterns of Evolution. 591 pp.Elsevier; Amsterdam.Google Scholar
Stitt, J. H. 1971. Repeating evolutionary pattern in Late Cambrian trilobite biomeres. J. Paleontol. 45:178–181.Google Scholar
Stitt, J. H. 1975. Adaptive radiation, trilobite paleoecology, and extinction, Ptychaspidid Biomere, Late Cambrian of Oklahoma. Pp. 381–390. In: Martinsson, A., ed. Evolution and Morphology of the Trilobita, Trilobitoidea and Merostomata. 467 pp.Fossils and Strata No. 4.Google Scholar
Taylor, M. E. 1968. Review of: The Mindyallan Fauna of Northwestern Queensland, by A. A. Öpik. J. Paleontol. 42:1319–1321.Google Scholar
Taylor, M. E. 1977. Late Cambrian of western North America: Trilobite biofacies, environmental significance, and biostratigraphic implications. Pp. 397–426. In: Kauffman, E. G. and Hazel, J. E., eds. Concepts and Methods of Biostratigraphy. 658 pp.Dowden, Hutchinson & Ross, Inc.; Stroudsburg, Pennsylvania.Google Scholar
Tchernycheva, N. E. 1959. Systeme Cambrien. Pp. 185–244. In: Markovsky, A. P., ed. Structure Géologique de l'U.R.S.S. Tome 1. Stratigraphie. (de Saint-Aubin, P. and Roger, J., trans.). 803 pp.Centre National de la Recherche Scientifique; Paris.Google Scholar
Tchernycheva, N. E., ed. 1965. Kembriyskaya Sistem. 596 pp. Nedra; Moscow.Google Scholar
Thayer, C. W. 1979. Biological bulldozers and the evolution of marine benthic communities. Science. 203:458–461.CrossRefGoogle ScholarPubMed
Valentine, J. W. 1969. Patterns of taxonomic and ecological structure of the shelf benthos during Phanerozoic time. Palaeontology. 12:684–709.Google Scholar
Valentine, J. W. 1972. Conceptual models of ecosystem evolution. Pp. 192–215. In: Schopf, T. J. M., ed. Models in Paleobiology. 250 pp.Freeman, Cooper & Co.; San Francisco, California.Google Scholar
Valentine, J. W. 1973. Evolutionary Paleoecology of the Marine Biosphere. 511 pp. Prentice-Hall; Englewood Cliffs, New Jersey.Google Scholar
Valentine, J. W. and Moores, E. M. 1970. Plate-tectonic regulation of faunal diversity and sea level: A model. Nature. 228:657–659.CrossRefGoogle ScholarPubMed
Valentine, J. W. and Moores, E. M. 1972. Global tectonics and the fossil record. J. Geol. 80:167–184.CrossRefGoogle Scholar
Van Valen, L. 1973. A new evolutionary law. Evol. Theory. 1:1–30.Google Scholar
Wade, M. 1968. Preservation of soft-bodied animals in Precambrian sandstones at Ediacara, South Australia. Lethaia. 1:238–267.CrossRefGoogle Scholar
Wade, M. 1969. Medusae from uppermost Precambrian or Cambrian sandstones, central Australia. Palaeontology. 12:351–365.Google Scholar
Wade, M. 1971. Bilateral Precambrian chondrophores from the Ediacaran fauna, South Australia. Proc. R. Soc. Victoria. 84:183–188.Google Scholar
Wade, M. 1972. Hydrozoa and Scyphozoa and other medusoids from the Precambrian Ediacara fauna, South Australia. Palaeontology. 15:197–225.Google Scholar
Wager, L. R. 1964. The history of attempts to establish a quantitative time-scale. Pp. 13–28. In: Harland, W. B. et al., eds. The Phanerozoic Time-Scale. A Symposium. 458 pp.Geol. Soc. London; London.Google Scholar
Walker, K. R. 1972. Community ecology of the Middle Ordovician Black River Group of New York State. Geol. Soc. Am. Bull. 83:2499–2524.CrossRefGoogle Scholar
Walker, K. R. and Ferrigno, K. F. 1973. Major Middle Ordovician reef tract in east Tennessee. Am. J. Sci. 273A:294–325.Google Scholar
Walker, K. R. and Laporte, L. F. 1970. Congruent fossil communities from Ordovician and Devonian carbonates of New York. J. Paleontol. 44:928–944.Google Scholar
Webb, S. D. 1969. Extinction-origination equilibria in late Cenozoic land mammals of North America. Evolution. 23:688–702.CrossRefGoogle ScholarPubMed
Whittington, H. B. 1966. Phylogeny and distribution of Ordovician trilobites. J. Paleontol. 40:696–737.Google Scholar
Williams, A. 1969. Ordovician faunal provinces with reference to brachiopod distribution. Pp. 117–154. In: Wood, A., ed. The Pre-Cambrian and Lower Paleozoic Rocks of Wales. 461 pp.Univ. Wales Press; Cardiff.Google Scholar
Yakobson, K. E. and Krylov, N. S. 1978. The lower boundary of the Vendian in its stratotype. Int. Geol. Rev. 20:709–718.CrossRefGoogle Scholar
Zhuravleva, I. T. 1970. Marine faunas and Lower Cambrian stratigraphy. Am. J. Sci. 269:417–445.CrossRefGoogle Scholar
Zhuravleva, I. T. 1972. Early Cambrian biogeography and geochronology according to the Archaeocyathi. 1968 Proc. IPU, XXIII Int. Geol. Congr., pp. 361–373.Google Scholar
Zhuravleva, I. T. and Miagkova, E. I. 1972. Archaeata—novaja grupa organizmov Paleozoja. Pp. 7–14. In: Paleontologija Miezdunarod Geol. Kongress XXIV Sessija. 131 pp.Nauka; Moscow.Google Scholar
Zhuravleva, I. T. and Miagkova, E. I. 1974. Spravnitelnaja kharakteristika Archeata i Stromatoporoidea. Pp. 63–70. In: Sokolov, B. S., ed. Ancient Cnidaria, v. 1. 363 pp.Nauka; Moscow.Google Scholar